Process for dyeing or printing cellulose with vat dyestuffs containing hydrophilic groups



United States Patent PRQCESS FOR DYEING 0R PRINTING CELLULOSE WITH VATDYESTUFFS CONTAG HYDRO- PHILIC GROUPS Kurt Weber, Max Staeuble, andHeinz Peter Schaub, Basel, Switzerland, assignors to Ciba Limited,Basel, Switzerland, a ccmpany of Switzerland No Drawing. Filed Jan. 31,1961, Ser. No. 85,973 Claims priority, application Switzerland, Feb. 2,1960, 1,091/60; Jan. 16, 1961, 461/61 13 Claims. (Cl. 8-35) Thisinvention provides a process for dyeing or printing textile materials,especially textile materials of cellulose, wherein there is used a vatdyestuif which contains at least one sulfonic acid amide group of whichthe nitrogen atom is bound to an aliphatic chain which contains asulfuric acid semi-ester group and contains at least three carbon atomsbetween the sulfuric acid semi-ester group and the amide nitrogen atom,and the dyestulf is reduced to the leuco form before or during thedyeing or printing process and the leuco-compound is oxidized on thefiber in the usual manner.

The aliphatic chain containing at least three carbon atoms which ispresent in the aforesaid vat dyestuffs, may be straight or branched. Thechain may consist of carbon and hydrogen atoms or may be interrupted bya hetero atom, more especially an oxygen, sulfur or nitrogen atom. Thereare advantageously used those vat dyestuffs of which the aliphaticamide-chain contains less than 10 members, that is to say, for example,3 to 8 CH or -CH-- groups and a hetero atom, and, if desired, a furthersulfato group.

The vat dyestuifs used in the process of the invention may belong to theanthraquinone, perylene, perinone or pyrene-quinone series or to theindigoid series or phthalocyanine series, especially cobaltphthalocyanine. As examples there may be mentionedacylaminoauthraquinones, such as l:-dibe-nzoylaminoanthraquinone, acondensation product of one molecular proportion of an acid dichloridewith two molecular proportions of 1- aminoanthraquinone orl-amino-5-benzoylamii1oanthraquinone. The vat dyestuffs may contain morehighly condensed ring systems, such as the pyranthrone, anthanthrone,dibenzpyrene-quinone or acedianthrone, and there may be mentioned moreespecially aminoor nitro-dibenzanthrones or nitrooramino-isodibenzanthrones, condensation products of aminodibenzanthroneswith halogenated polycyclic compounds or mixed condensation products ofaminodibenzanthrone or an aminoanthraquinone with a halogenatedpolycyclic compound, and also vat dyestuifs which contain fused on orfused in hetero rings, for example, indanthrone, fiavanthrone,N:N-diethyl-dipyrazoleanthrone, S-benzoylaminoanthrapyrimidine orperyle-ne-tetracarboxylic acid diimides or perinone dyestuffs obtainableby the condensation naphthalene tetracarboxylic acid with 2 molecularproportions of ortho-phenylenediarnine or dyestuiis of the formulams/\C=C/ S \i "ice ' yalkyl-sulfonamide so obtained with concentratedsulfuric acid or chlorosulfonic acid.

The dyeing process is carried out in the presence of an alkali,especially an alkali metal hydroxide, and a reducing agent.

As reducing agents there may be used strong reducing agents, such assodium hydrosulfite, or thiourea dioxide, or weak reducing agents, suchas sodium sulfide, sodium hydrosulfide, glucose or hydrazine. Theproportion of the reducing agent may vary Within wide limits. In generalit is suflicient to use a considerably smaller proportion of reducingagent than is necessary in dyeing with vat dyestulfs by the knownmethods. The dyeing may be carried out, for example, by the exhaustionmethod. In this case the material to be dyed is treated in a solution ofthe dyestuif which contains the alkali and the reducing agent,advantageously at a moderately raised temperature, more especiallywithin the range of 20 C. to C. The oxidation of the leuco-compoundfixed on the fiber and the after-treatment, such as rinsing and soapingat the boil, are carried out by the methods usual in thevat dyestulfindustry.

In an especially advantageous form of the process an aqueous solution ofthe vat dyestufi to be used is applied to the material by padding. Forthis purpose the mate rial to be dyed is impregnated with the dyestuflfsolution in the cold or at a moderately raised temperature, and theimpregnated material is squeezed in the usual manner. Advantageously thematerial is so squeezed that it retains 50 to of its weight of dyestuffssolution. The treatment with alkali and a reducing agent is carried outafter the impregnation, and advantageously after drying the impregnatedmaterial. For this purpose the treated material is impregnated with anaqueous solution containing the alkali and the reducing agent, thensqueezed and steamed in orderto fix the dyestuff. The aftertreatment,namely rinsing with cold water, oxidation, if desired, with the additionof an oxidizing agent, for example, hydrogen peroxide or sodium borate,acidification and soaping at the boil, is carried out in the usualmanner.

Instead of applying the dyestuif to the material by impregnation it maybe applied by printing. In this case there is used a printing colorwhich contains the dyestutf and the additions customary in printing withvat dyestuffs, such as potassium carbonate, hydrosulfite or rongalite,and thickening agent.

The process of the invention leads to excellent dye ings and prints ontextile materials, more especially textile materials of cellulose It hasbeen surprisingly found that in the process of the invention thesulfuric acid semiester radical splits off so rapidly and completelythat the normal dyeing or printing conditions such as are customary withvat dyestuffs, and alkalies of the usual kind and in the sameproportion, can be used. In certain cases it may be necessary to avoidusing conditions, such as an especially low dyeing temperature and/ or apH-value very close to the neutral point, which retard the splitting offof the aforesaid radical. If, nevertheless, dyeing is carred out at alow temperature, or in the case of the padding or printing process,steaming is carried out for a short time, it is desirable to carry outan after-treatment with an alkali metal hydroxide, for example, with asoap bath containing, per liter, to ml. of sodium hydroxide. In thismanner the production of fast and full dyeings and prints is ensured.

By the process of this invention there are obtained strong dyeings orprints, which possess excellent properties of fastness, for example, agood fastness to light and a good fastness to kier boiling. As comparedwith the conventional methods of vat dyeing, the process of theinvention has the important advantage that the dyestuffs are applied ina water-soluble form and therefore more easily vattable dyestuffs can beused. Processes are known in which vat dyestuffs containing theaforesaid sulfonarnide groups are used, but without a reducing agent.The dyeing s produced by these processes are considerably weaker anduseless for practical purposes.

The following examples illustrate the invention, the parts andpercentages being by weight:

EXAMPLE 1 0.15 part of the dyestuff of the formula are dissolved inparts of water at 70 C. The resulting blue solution is poured into asolution, heated at 70 C., of 2 parts by volume of sodium hydroxidesolution of 30% strength and 1.2 parts of sodium hydrosulfit e in 350parts of water, whereupon vatting sets in spontaneously. 10 parts ofcotton are dyed in the dyebath so prepared for 45 minutes at to C. withaddition of 8 parts of sodium chloride. The dyed cotton is oxidized,washed, acidified, once more thoroughly rinsed, and soaped at the boil.A strong clear blue dyeing is obtained which has excellent properties offastness.

When dyeing is performed at 60 to 70 C. in a dyebath which contains 6parts by volume of sodium hydroxide solution of 30% strength and 1.2parts of sodium hydrosulfite, without addition of sodium chloride, anidentical dyeing is obtained.

The above dyestuff can be prepared by condensing dibenzanthronedisulfochloride with 4-aminobutanol and esterifying the hydroxyl groupswith sulfuric acid.

Dyeing in an identical manner can be carried out with the dyestuffobtained by condensing isodibenzanthrone disulfochloride with4-aminobutanol and esterifying the hydroxyl group wtih sulfuric acid.The resulting dyeing is of a reddish blue shade and has good propertiesof fastness.

EXAMPLE 2 0.75 part of the dyestuif of the formula is pasted. in 250parts of warm water. The resulting dyestufif suspension is added to asolution, heated at 50 C., of 10 parts by volume of sodium hydroxidesolution of 30% strength and 6 parts of sodium hydrosulfite in 1750parts of water, whereupon vatting sets in spontaneously. 50 parts ofcotton are dyed in the dyebath so prepared for 45 minutes at 50 to 60 C.with addition of 60 parts of sodium chloride. The dyed cotton isoxidized, washed, acidified, once more thoroughly rinsed, and soaped atthe boil. A yellow dyeing of good properties of fastness is obtained.

The above dyestuff is obtained by monocondensation of cyanuric chloridewith 3-aminobenzene-5-hydroxybutyl sulfonarnide in acetone, condensingthe reaction product with 1 molecular proportion ofl-amino-S-benzoylaminoanthraquinone and esterifying the hydroxyl groupwith sulfuric acid.

EXAMPLE 3 0.75 part of the dyestuff of the formula OSOaH is pasted in250 parts of warm water. The resulting dyestuff suspension is added to asolution, heated at 60 C., of parts by volume of sodium hydroxidesolution of 30% strength and 6 parts of sodium hydrosulfite in 1750parts of water, whereupon vatting sets in spontaneously. 50 parts ofcotton are dyed in the resulting dyebath for 45 minutes at 60 to 70 C.with addition of 60 parts of sodium chloride. The dyed cotton isoxidized, washed, acidified, once more thoroughly rinsed, and soaped, atthe boil. A brilliant red dyeing of good fastness properties isobtained.

The above dyestutf can be prepared as follows: 9.8 parts of thedisulfochloride of the formula prepared from the appropriate diamine bycondensing it with benzoyl chloride-4-sulfochloride in nitrobenzene arestirred in 150 parts of nitrobenzene at 120 C. 4 parts of3-arninopropanol-(1) in parts of nitrobenzene are then slowly addeddropwise in the course of 1 hour, the mixture is stirred on for 4 hoursat 120 C. and then for 1 more hour each at 140 C. and 180 C. Afterhaving cooled, the mixture is filtered, and the filter residue is washedsuccessively with benzene, alcohol and water, and dried.

9 parts of the condensation product obtained in this manner are stirredinto 180 parts of concentrated sulfuric acid at 0 to 5 C. and dissolvedtherein. The whole is then cautiously poured over ice and filtered. Themoist filter cake is suspended in about 500 parts of water andneutralized with sodium hydroxide solution, then filtered and driedunder vacuum at 60 to 70 C.

EXAMPLE 4 (Exhaustion Method) 5 parts of the dyestutf of the formulashown in Example l are dissolved at 80 C. in 100 parts of water,whereupon 5 parts by volume of sodium hydroxide solution of 40% strengthand 3 parts of sodium hydrosulfite are added. parts of cotton are dyedin the dyebath thus prepared for 45 minutes at 80 C. with addition ofparts of sodium chloride. The dyed cotton is oxidized, rinsed,acidified, thoroughly rinsed, and soaped. A reddish blue dyeing isobtained.

Instead of sodium hydrosulfite, there may be used thiourea dioxide orsodium sulfide.

EXAMPLE 5 (Pad-Jigging Method) ple 4.

Satisfactory dyeings are also obtained when sodium sulfide or thioureadioxide is used instead of sodium hydrosulfite.

EXAMPLE 6,

(Pad-S teaming Method) A cotton fabric is padded at 25 C. with asolution containing in 1000 parts of water 10 parts of the dyestuff ofthe formula shown in Example 1 until its weight shows an increase of80%. The fabric--if desired after having been intermediately driedisthen impregnated in a bath containing in 1000 parts of water 200 partsof sodium 6 chloride, 50 parts by volume of sodium hydroxide solution of40% strength and 30 parts of sodium hydrosulfite. The fabric is thensqueezed to a weight increase of 70 to 100%, steamed for 50 seconds, andthen finished as described in Example 4.

When the fabric is steamed for 120 seconds, somewhat better results areobtained.

EXAMPLE 7 (Pad-Roll Method) A cotton fabric is impregnated at 25 C. witha padding liquor containing per 1000 parts of water 10 parts of thedyestuif prepared as described below, 50 parts by volume of sodiumhydroxide solution of 40% strength and 40 parts of Rongalit, and thensqueezed to a weight increase of After having been so squeezed, thefabric is heated to 80 to C. in an infra-red zone or a steaming channel,then introduced into a preferably airfree chamber maintained at 80 to 85C., and kept there for 2 to 4 hours in the rolled-up state. Finishingfollows the procedure described in Example 4.

PREPARATION OF THE DYESTUFF 50 parts of aminodibenzanthrone (nitrogencontent=3.68%) are entered at room temperature with cooling in 150 partsby volume of chlorosulfonic acid, and the mixture is then heated for 2hours at 125 C. When this internal temperature has been reached, thereaction mixture is kept for 2 hours at 125 C., during which a vigorouscurrent of hydrochloric acid and sulfur dioxide escapes. The heating isthen discontinued and the batch is cooled to 80 C. While maintaining aninternal temperature of 70 to 80 C., a total of 75 parts by volume ofthionyl chloride is then added dropwise. When all thionyl chloride hasbeen dropped in, and the internal temperature is raised to 85 C., a weakreflux of thionyl chloride should be noticed. The batch is kept forabout 30 to 40 minutes at this temperature, then cooled, and poured overice. When decomposition has taken place, the mixture issuction-filtered, and the filter residue is washed with cold Water untilthe washings display only a Weak acid reaction (pl-i=5 to 6). Thesulfochloride thus prepared is added to a solution of 200 parts ofNzN-dihydroxy-ethyl-propylenediamine-(1:3) in 1000 parts of water whilecooling with ice and then stirred overnight. The following morning thereaction mixture is heated for 2 to 3 hours at 50 to 60 C., then cooledto room temperature, and the dyestuff is suctioned off. The filter cakeis suspended in methanol and again suction-filtered. The dried dyestuffis added with cooling to 200 parts by volume of sulfuric acid ofstrength and the whole is stirred for several hours at 20 to 25 C., thenpoured over ice, suctioned ofi, and the ester is suspended in water andadjusted with NaOI-I to pH=8. The dyestuif is suctioned off and dried ina vacuum cabinet at 40 to 50 C.

EXAMPLE 8 (Single-Bath Steaming Method) A cotton fabric is impregnatedat 25 C. with a padding liquor containing per 1000 parts of water 10parts of the dyestuff used in Example 7, 50 parts of urea, 50 parts byvolume of sodium hydroxide solution of 40% strength and 40 parts ofRongalit. The fabric is then steamed if desired after having beenintermediately dried-for 5 minutes, and the dyeing is finished asdescribed in Example 4.

7 EXAMPLE 9 (Therm ofixing Method) EXAMPLE 10 (Printing Method) Aprinting paste is prepared which contains 20 parts of the dyestufr ofthe formula 200 parts 238 parts 400 parts 60 parts urea of water ofsodium alginate thickening 50:1000

of potassium carbonate solution of 30% strength 2 parts of sodiumhydroxide solution of 40% strength, and 80 parts of Rongalit 1000 partsThe printing paste is then applied on a roller printing machine to acotton fabric. The printed fabric is dried and steamed for 8 minutes at100 C. in a Mather-Flatt ager, and then finished as descri ed in Example4.

'A similar, good result is obtained on spun rayon fabric. By the methoddescribed above there is obtained a grey print with the dyestuff used inExample 7.

EXAMPLE 11 0.5 part of the dyestuif used in Example 7 is dissolved in1000 parts of water v at 80 C., whereupon 5 parts by volume of sodiumhydroxide solution of 40% strength and 3 parts of sodium hydrosulfiteare added. 25 parts of cotton are dyed in the resulting dyebath for 45minutes at 80 C with addition of 30 parts of sodium chloride. The dyedcotton is oxidized in air, rinsed, acidified, thoroughly rinsed, andsoaped. A grey dyeing results.

A similar dyeing is obtained with the dyestufi prepared bysulfochlorination of aminodibenzanthrone with chlorosulfonic acid,condensation with N-methyl-N-hydroxyethyl-propylenediamine-(1:3) andesterification with sulfuric acid of 100% strength.

Similar dyeings can be obtained with the dyestuffs obtained bysulfochlorinating the dyestuffs shown in column I of the following tableat the temperature listed in column llll, condensing the resultingsulfochloride with the amine shown in column W and converting theresulting sulfonamide with concentrated sulfuric acid into the sulfuricacid semi-ester. The shades thus obtained are listed in column V.

I II III IV V N-content C. inpereent 1 Nitrodibenz- 3.68 130NzN-dihydroxy- Grey anthrono. ethyl-propylenediamine- (1:3). 2.Amiuodibenz- 3.68 d Do.

anthrone.

3.68 Do. 3.68 D9. 3. 55 Do. 1 a7 Do. .do 3.88 125 do Do. trodibenz- 130N-methyl-N-hy- Do'. anthrone. droxyethyl-propylenediamine- 1:3). a...Aminodibenz- 3.68 120 do D0.

anthrone. 10 do 3.68 130 do D0. 11... .do 3.68 140 do Do. 12.-. d0 3. 55125 1o Do. 13 -.d0 3.7 125 .do Do. 14". d0 3.88 125 .do 120.

EXAMPLE 12 0.1 part of the dyestufl obtained as described below is usedas described in Example 1. A grey dyeing of good fastness properties isobtained.

PREPARATION OF THE DYESTUFF parts of a condensation product from 4molecular proportions of aminodibenzanthrone (nitrogen content=3.58% and1 molecular proportion of tetrabromopyranthrone (which can be prepared,for example, by the process described in Fiat Final Report 1313, volume11, page 118, for Indanthren Direct Black RB) are added at roomtemperature with cooling to 200 parts by volume of chlorosulfonic acidand then heated for 2 hours at 130 C. When this internal. temperaturehas, been reached, the reaction mixture is maintained for 2 hours atthis temperature, while a vigorous current of hydrochloric acid andsulfur dioxide escapes. The heating is then discontinued and the batchis cooled to 80 C. While maintaining the internal temperature at to C.,a total of 75 parts by volume of thionyl chlo- 5 ride are then addeddropwise. When all thionyl chloride has been dropped in and the internaltemperature is raised to C., a weal; reflux of thionyl chloride shouldbe noticeable. The batch is kept for about 30 to 4-0 minutes at 85 C.,then cooled, and poured over ice. When decomposition has taken place,the whole is suctionfiltered and washed with cold water until thewashings run only slightly acid (pH 5 to 6). The resulting sulfochlorideis added to a solution of 200 parts ofN:N-dihydroxyethyl-propylenediamine-(l:3) in 1000 parts of water wi hice-cooling, and the mixture is stirred overnight. G n the followingmorning the reaction mixture is heated for 2 to 3 hours at 50 to 60 (3.,then cooled to room temperature, and the dyestuil' is suctioned off. Thefilter cake is suspended in methanol and again suction-filtered. Thedried dyestufi is added with cooling to 250 parts-by volume of sulfuricacid of strength and the mixture is stirred for several hours at 20 to25 0., then poured over ice, suction-filtered, and the ester issuspended with water and adjusted with NaOH to pH=8.

9 The dyestutf is suctioned oif and dried in a vacuum cabinet at 40 to50 C.

In the same manner dyeings may be produced with the dyestuffs obtainedin a similar manner from the sulfochloride (a) of the condensationproduct from 3 molecular proportions of aminodibenzanthrone (nitrogencontent=3.68%) with 1 molecular proportion of tribromopyranthrone, or

(b) of the condensation product from 3 molecular proportions ofaminodibenzanthrone (nitrogen content- 3.68%) with 1 molecularproportion each of aminoanthraquinone and tetrabromopyranthrone,

(c) of the condensation product from 2 molecular proportions ofaminodibenzanthrone (nitrogen content=3.68%) with 2 molecularproportions of l-amino- 4-anilidoanthraquinone and 1 molecularproportion of tetrabromopyranthr'one, or

(d) of the condensation product from 2 molecular proportions ofaminodibenzanthrone (nitrogen content=3.68%), and 1 molecular proportioneach of l-amino-anthraquinone, and 1-amin0-4-anilidoanthraquinone andtetrabromopyranthrone.

EXAMPLE '13 1.0 part of the dyestulf of the probable formula aredissolved in 50 parts of Water With addition of 3 to drops of sodiumhydroxide solution of 30% strength, and this solution is used asdescribed in Example 1. A strong, reddish blue dyeing of excellentfastness properties is obtained.

The above dyestuff can be prepared by condensing isodibenzanthronedisulfochloride with 2 (B aminoethylarnino)-ethanol and esterifying theresulting product with concentrated sulfuric acid.

Dyeing may be performed in a similar manner with the dyestuffs obtainedby condensing a sulfochloride in column I of the following table with anamine in column II, condensing the resulting chloroalkylamide With anamine in column III and then esterifying the product with sulfuric acid.The shades produced are listed in'col .umn IV.

I II III IV 1st amine 2nd amine 1-.-- Isodibeuzan- NH2-GH2OH2CL-NHz-CHzCHzOH... Blue.

thronedisulfochloride.

1 2- do NHOHgOHzCl NHz-OHzCHaOH--. Do. 3.... Dibenzan- NHz-OHgOI-lzCL.NHz-CHzCHzOH-.. Navy.

' thronedisulfochloride.

S 4 do NH-CHzCHzCl--- NHrOHBCHiOH Do.

EXAMPLE 14 0.5 part of the dyestulf which in the form of its free acidprobably corresponds to the formula is used as described in Example 1. Aviolet dyeing is obtained which has excellent properties of fastness.

The dyestuif can be prepared by condensingisodibenzanthrone-disulfochloride with 3-aminopropanol and esterifyingthe resulting product with concentrated sulfuric acid.

Dyeing may be performed in a similar manner with the dyestuffs obtainedby condensing the sulfochloride of a Vat dyestulf listed in column I ofthe following table with the same amine, followed by identicalesterification. The shades obtained are shown in column 11.

Olive.

l I N N 0 C O 4 Golden yellow.

C CO N N What is claimed is:

l. A process for dyeing and printing cellulose-containing textilematerials, wherein there is used a vat dyestuif which contains at leastone sulfonic acid amide group of which the nitrogen atom is bound to analiphatic chain which contains a sulfuric acid semi-ester group and atleast three carbon atoms between the sulfuric acid serniester group andthe amide nitrogen atom, and the dye stufl? is reduced to the leuco formand applied to the material as leuco-compound which is then reoxidizedon the fiber.

2. Process for dyeing and printing cellulose-containing textilematerials with a vat dyestuflf which contains at least one substituentof the formula in which n and m each represents a whole positive numberup to and including two and Z represents a member selected from thegroup consisting of the --CH the groups, the process being carried outin the presence of an alkali and a reducing agent and the dyestufl leucocompound being then reoxidized on the fiber.

3. Process for dyeing and printing cellulose-containing textilematerials with a dibenzanthrone vat dyestufi which contains at least onesulfonic acid amide group whose nitrogen atom bears analiphatic chain ofat least 4 and at most 7 carbon atoms, which chain contains a sulfategroup, the process being carried out in the presence of an alkali and areducing agent and the dyestuft leuco compound being then reoxidized onthe fiber.-

4. Process for dyeing and printing cellulose-containing textilematerials with a isodibenzanthrone vat dyestuif which contains at leastone sulfonic acid amide group whose nitrogen atom bears an aliphaticchain of at least 4 and at most 7 carbon atoms, which chain contains asulfato group, the process being carried out in the presence of analkali and a reducing agent and the ,dyestuff leuco compound being thenreoxidized on the fiber.

5. The process of claim 3 wherein an aminodibenzanthrone. is used.

6. Process for dyeing and printing cellulose-containing textile.materials with a benzoylarninoanthraqllinone vat dyestuit which containsat least one sulfonic acid amide group whose nitrogen atom bears analiphatic chain of at least 4 and at most 7 carbon atoms, which chaincontains a sulfato group, the processbeingv carried out in the presence.of an alkali. anda reducing agentv andthe dyestuff leuco compound: beingthen reoxidized on, the fiber.

7'. Process for dyeing and printing cellulose-containing textilematerials with a condensation product of an aminodibenzanthrone. withtetrabrornpyranthrone which contains at least one sulfonic acid amide,group whose nitrogen atom bears an aliphatic chainv of at least 4. and:at

10st 7 carbon atoms, which chain contains a sulfato group, the processbeing'carried out in the presence of an alkali and a reducing agent andthe dyestuil leuco compound being then reoxidized on the fiber.

8. The process for. dyeing and printing cellulose fibers with thedyestuif oftthe formula in the presence of an alkali and a reducingagent and the dyestuff leuco compound being then reoxidized on thefiber.

9. The process for dyeing and printing cellulose fibers with thedyestuif of the formula in which n is 1-3, in the presence of an alkaliand a 1 3 reducing agent and the dyestuff leuco compound being thenreoxidized on the fiber.

10. The process for dyeing and printing cellulose fibers with thedyestufi of the formula in the presence of an alkali and a reducingagent and the dyestuif leuco compound being then reoxidized on thefiber.

11. The process for dyeing and printing cellulose fibers with thedyestuif of the formula in the presence of an alkali and a reducingagent and the dyestulf leuco compound being then reoxidized on thefiber.

1 4 12. The process for dyeing and printing cellulose fibers with thedyestuii of the formula CHgCHzOSOaH in Which n is 1-3, in the presenceof an alkali and a reducing agent and the dyestuif leuco compound beingthen reoxidized on the fiber.

References Cited in the file of this patent UNITED STATES PATENTS2,576,847 Mecco Nov. 27, 1951 2,895,785 Alsberg et al. July 21, 19592,995,412 Kleb Aug. 8, 1961 3,022,304 Staeuble et al. Feb. 20, 19623,029,236 Staeuble et al. Apr. 10, 1962 3,066,005 Wedemeyer et a1 Nov.27, 1962

1. A PROCESS FOR DYEING AND PRINTING CELLULOSE-CONTAINING TEXTILEMATERIALS, WHEREIN THERE IS USED A VAT DYESTUFF WHICH CONTAINS AT LEASTONE SULFONIC ACID AMIDE GROUP OF WHICH THE NITROGEN ATOM IS BOUND TO ANALIPHATIC CHAIN WHICH CONTAINS A SULFURIC ACID SEMI-ESTER GROUP AND ATLEAST THREE CARBON ATOMS BETWEEN THE SULFURIC ACID SEMIESTER GROUP ANDTHE AMIDE NITROGEN ATOM, AND THE DYE STUFF IS REDUCED TO THE LEUCO FORMAND APPLIED TO THE MATERIAL AS LEUCO-COMPOUND WHICH IS THEN REOXIDIZEDON THE FIBER.